login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A084733
Squares which are the sum of at least three successive terms of a geometric progression.
1
49, 121, 169, 196, 225, 400, 441, 484, 676, 784, 900, 961, 1089, 1225, 1521, 1600, 1764, 1849, 1936, 2025, 2401, 2704, 3025, 3136, 3249, 3600, 3844, 3969, 4225, 4356, 4900, 5329, 5625, 5929, 6084, 6400, 7056, 7225, 7396, 7744, 8100, 8281, 8649, 9604
OFFSET
1,1
COMMENTS
The partial sums of three or more successive terms of the sequence (2^n), 1,2,4,8,16,32,... is given by 7,14,15,28,30,31,...hence the square of the terms of this sequence are members. The same can be extended for any sequence of the form k^n.
EXAMPLE
49 is a member as 49=7^2 = 7 + 14 + 28.
400 is a member as 400 = 20^2 = 1 + 7 + 7^2 + 7^3.
CROSSREFS
Intersection of A000290 and A376298.
Sequence in context: A348054 A090095 A163245 * A338499 A227863 A339131
KEYWORD
nonn
AUTHOR
Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 14 2003
EXTENSIONS
More terms from David Wasserman, Jan 03 2005
Offset changed by Andrew Howroyd, Sep 19 2024
STATUS
approved